JP2002280637A - Magnetoresistive effect element and its manufacturing method, magnetic random access memory, portable terminal apparatus, magnetic head, and magnetic reproduction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetoresistive effect element that is magnetically stabilized, and has a reduced switching magnetic field, and to provide a method for manufacturing a magnetoresistive effect element. SOLUTION: The width of an element end section is widened as compared with a center section, and is set to a shape that is asymmetrical to the axis of easy magnetization and at the same time is nearly rotary-symmetrical when a film surface vertical direction is used as an axis. The S-shaped structure of a magnetic domain is stabilized, and the switching magnetic field is reduced. Also, the overlap of linear pattern etching is used with EB drawing for obtaining the structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetoresistive element, a method of manufacturing the same, a magnetic random access memory, a portable terminal device, a magnetic head, and a magnetic reproducing device.

[0002]

2. Description of the Related Art Various types of solid-state magnetic memories have been conventionally proposed. In recent years, a magnetic random access memory (MR) using a magnetic element exhibiting a giant magnetoresistance effect has been proposed.
AM) has been proposed, and in particular, attention has been focused on a magnetoresistive element (TMR element) using a ferromagnetic tunnel junction as a magnetic memory.

[0003] The ferromagnetic tunnel junction mainly has a ferromagnetic layer 1 /
It is composed of a three-layer film of an insulating layer / ferromagnetic layer 2, and a current flows through the insulating layer by tunneling. In this case, the junction resistance changes in proportion to the cosine of the relative angle of the magnetization of the ferromagnetic layers 1 and 2. Therefore, the resistance value has a minimum value when the magnetizations of the ferromagnetic layers 1 and 2 are parallel, and has a maximum value when the magnetizations are antiparallel. This is called the tunnel magnetoresistance (TMR) effect. For example, in a recent document (Appl. Phys. Lett. 77, 283 (2000)), TM
It is reported that the change in resistance due to the R effect is as high as 49.7% at room temperature.

In a magnetic memory device including a ferromagnetic tunnel junction as a memory cell, one magnetization of the ferromagnetic layer is fixed as a reference layer, and the other ferromagnetic layer is a storage layer.
In this cell, information is stored by associating binary information "0" and "1" with the arrangement of magnetization of the reference layer and the storage layer being parallel or antiparallel. In writing of recorded information, the magnetization of the storage layer is reversed by a magnetic field generated by passing a current through a write wiring provided separately for the cell. Reading is performed by flowing a current through the ferromagnetic tunnel junction and detecting a resistance change due to the TMR effect. A magnetic memory device is configured by arranging a large number of such memory cells.

The actual configuration is such that, for example, like a DRAM, a switching transistor is arranged for each cell and peripheral circuits are incorporated so that an arbitrary memory cell can be selected. Further, a method of incorporating a ferromagnetic tunnel junction together with a diode at a position where a word line and a bit line cross each other has been proposed (US Pat. No. 5,640,104).
No. 343, 5, 650, 958).

Now, considering the high integration of a magnetic memory device using a ferromagnetic tunnel junction as a memory cell, the size of the memory cell is reduced, and the size of the ferromagnetic material constituting the cell is necessarily reduced. In general, the smaller the ferromagnetic material, the greater its coercive force.

[0007] The magnitude of the coercive force is a measure of the magnitude of the switching magnetic field required for reversing the magnetization, and this means an increase in the switching magnetic field. Therefore, when writing information, a larger current must be applied to the write wiring, which results in an undesirable result of an increase in power consumption. Therefore, reducing the coercive force of the ferromagnetic material used for the memory cell of the magnetic memory is an important issue in putting a highly integrated magnetic memory into practical use.

When used as a memory cell of a magnetic memory, it is generally considered that a ferromagnetic material having a rectangular planar shape is used. However, in the case of a rectangular micro-ferromagnetic material, it is known that a special magnetic domain called an edge domain occurs at an end (for example, J. Ap.
p. Phys. 81, 5471 (1997)). This is because, in order to reduce the demagnetizing field energy on the short side of the rectangle, a pattern in which the magnetization rotates in a spiral along the side is formed. An example of such a magnetic structure is shown in FIG. 45. In the central part of the magnetized region, magnetization occurs in a direction according to the magnetic anisotropy, but at both ends, the magnetization is in a different direction from the central part. Occurs.

[0009] Considering the magnetization reversal of this rectangular ferromagnetic material, it is known that an edge domain grows and proceeds so as to enlarge the region. Here, considering the edge domains at both ends of the rectangle, a case where they are oriented in parallel to each other (FIG. 45 (a), S type structure) and a case where they are oriented in antiparallel direction (FIG. 45 (b) C type) Structure). 360 if anti-parallel
Since a magnetic domain wall is formed, the coercive force increases. To solve this problem, it has been proposed to use an elliptical ferromagnetic material as the storage layer (US Pat. No. 5,757,
695). This uses the property that the edge domain is very sensitive to the shape of the ferromagnetic material, and suppresses the generation of the edge domain that occurs at the end of a rectangle or the like, and realizes a single magnetic domain. Since the reversal can be performed uniformly over the entire body, the reversal magnetic field can be reduced.

In addition, it has been proposed to use a ferromagnetic material having a shape having a non-perpendicular angle at its corner, such as a parallelogram, as the storage layer (Japanese Patent Laid-Open No. 11-273337).
reference). In this case, the edge domain exists, but does not occupy a large area as in the case of the rectangular shape, and the magnetization can be almost uniformly reversed without generating complicated minute domains in the process of magnetization reversal. As a result, the switching magnetic field can be reduced.

On the other hand, in a multilayer film including at least two ferromagnetic layers and having a non-magnetic layer interposed therebetween, although the shape remains rectangular, the antiferromagnetic layer is formed between the ferromagnetic layers. It has been proposed to use those containing magnetic coupling (JP-A-9-25162, Japanese Patent Application No. 11-26).
3741, U.S. Pat. No. 5,953,248).

In this case, the two ferromagnetic layers have different magnetic moments or thicknesses, and the magnetizations are in opposite directions due to antiferromagnetic coupling. Therefore, the magnetizations effectively cancel each other, and the entire storage layer can be considered to be equivalent to a ferromagnetic material having a small magnetization corresponding to the difference in magnetic moment or the difference in film thickness in the easy axis direction. When a magnetic field is applied in a direction opposite to the direction of the small magnetization in the easy axis direction of the storage layer, the magnetization of each ferromagnetic layer is inverted while maintaining the antiferromagnetic coupling. In this structure, the influence of the demagnetizing field is small because the magnetic field lines are closed, and the switching magnetic field of the recording layer is determined by the coercive force difference of each ferromagnetic layer.

By the way, in the TMR element applied to the MRAM, a submicron element size is required due to a demand for high integration. Therefore, the submicron size T
Example of manufacturing an MR element using electron beam (EB) lithography (WJ Ga11agher et al., J. Appl. Phys. 81, 3741 (1
997)) will be briefly described with reference to a cross-sectional view (left side) and a top view (right side) of FIG.
First, as shown in FIG. 46A, a multilayer structure including a three-layer structure of a lower electrode 462 mainly made of a magnetic metal, an Al oxide barrier 463, and an upper electrode 464 mainly made of a magnetic metal is formed on a Si substrate 461. The lower electrode is formed by depositing with a magnetron sputtering apparatus and etching the multilayer structure using photoresist and ion milling (here, only a part near the junction of the lower electrode is shown).
Next, as shown in FIG. 46 (b), a pattern of a negative EB resist 456 is formed at the bonding portion by EB drawing, and a second ion milling is performed using the pattern to form a submicron-size bonding pattern. Form. In this ion milling, control is performed such that etching is stopped at an upper portion of the lower electrode 462 through the oxide barrier 463.

Next, as shown in FIG. 46C, the SiO ₂ insulating film 46 is left while the EB resist 465 is left at the junction.
6 is deposited by a magnetron sputtering apparatus. Finally, as shown in FIG. 46D, a contact hole is exposed in a self-aligned manner on the junction by a lift-off process using an EB resist under the SiO ₂ insulating film. The wiring 467 is formed by patterning using lift-off of a photoresist, and a contact is formed on the upper electrode.

A self-aligned TMR using this EB drawing
A TMR element having a submicron junction size has been obtained by the element manufacturing method. However, EB lithography can be directly performed on a multilayer structure having a basic structure of ferromagnetic metal / oxide green body / ferromagnetic metal. There were some problems to do.

In FIG. 46B, a resist pattern of a submicron size is formed on a joint by EB lithography in the EB lithography process. The scattering effect is stronger than that of the semiconductive material, so that the so-called proximity effect in which the resulting drawing pattern is greatly spread becomes remarkable, and the fineness and controllability of the drawing pattern shape are lost. As a result, even when a rectangle is drawn as the shape of the joint as shown in FIG. 46 (b), the actually obtained shape is a shape in which the sharpness of the corners is significantly lost.

Here, there is a close relationship between the planar shape of the junction of the TMR element and the coercive force (Hc), which is its magnetic property, and a rectangle with rounded corners has a greater sharpness than a rectangle with sharp corners. It has been found that the holding force is also increased by about twice. As a result, there is a problem that a TMR element having a low coercive force characteristic important for the operation of the MRAM cannot be obtained. .

[0018]

As described above, the reduction of the magnetic field (switching magnetic field) for reversing the magnetization of the recording layer is as follows.
It is an indispensable element in a magnetic memory, and it has been proposed to use several shapes and a multilayer film including antiferromagnetic coupling.

However, in a small ferromagnetic material placed in a small magnetic memory cell used for a highly integrated magnetic memory, for example, when the width of the short axis becomes several microns to sub-micron or less, the magnetization region becomes small. It is known that a magnetic structure (edge domain) different from the magnetic structure of the central portion of the magnetic body occurs at the end of the magnetic material due to the influence of the demagnetizing field.

In the case of a fine magnetic material such as used in a cell of a highly integrated magnetic memory, the edge domain generated at its end is greatly affected as described above, and the change of the magnetic structure pattern upon magnetization reversal becomes complicated. Become. As a result, the coercive force increases and the switching magnetic field increases.

As a method of preventing such a complicated change in magnetic structure as much as possible, fixing an edge domain has been considered (US Pat. No. 5,741).
8,524, JP-A-2000-100153).

Thus, the behavior at the time of magnetization reversal can be controlled, but the switching magnetic field cannot be substantially reduced. Further, another structure needs to be added to fix the edge domain, which is not suitable for high density.

As mentioned above, a submicron ferromagnetic material /
An EB drawing process has been used to fabricate a TMR element having an insulator / ferromagnetic junction. However, it is difficult to form a fine pattern whose shape is controlled significantly due to the proximity effect of an EB cat image on a metal multilayer structure. Therefore, TMR with low holding power characteristics
There was a problem that it was difficult to obtain an element. This is essentially due to a problem common to photolithography that, in the vicinity of the resolution limit in the lithography process, when a rectangular shape is formed, the sharpness of the corner is significantly lost.

A first object of the present invention is to provide a magnetic memory cell which is small enough to be integrated at a high density as described above and has a stable magnetic structure without adding a new structure. Another object of the present invention is to reduce a switching magnetic field required for writing information into a cell at the same time. It is still another object of the present invention to provide a magnetic memory cell which is magnetically stable and has a sufficiently reduced switching magnetic field, and provides a random-accessible non-destructive magnetic memory using such a magnetic memory cell.

A second object of the present invention is to provide a manufacturing method suitable for the magnetoresistance effect element of the present invention, which is easy and has high productivity.

[0026]

According to the present invention, in order to solve the above-mentioned problems, a first magnetoresistive element of the present invention comprises:
A first ferromagnetic layer, an insulator layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the insulator layer; A tunnel current flows between the first ferromagnetic layer and the second ferromagnetic layer, and detects the tunnel current or a voltage generated between the first and second ferromagnetic layers. Therefore, the planar shape is characterized in that the width at the end is larger than the width at the center.

Further, the second magnetoresistive element of the present invention comprises a first ferromagnetic layer, a first insulator layer formed on the first ferromagnetic layer, and a first insulating layer formed on the first ferromagnetic layer. A second ferromagnetic layer formed on the body layer, a second insulator layer formed on the second ferromagnetic layer, and a third ferromagnetic layer formed on the second insulator layer. A magnetoresistive effect element having a ferromagnetic layer, wherein a planar shape of the magnetoresistive element is larger at an end portion than at a central portion.

That is, according to the present invention, in a magnetoresistive element including a ferromagnetic layer used as a magnetic memory cell, a magnetic structure peculiar to a fine ferromagnetic material is used, and the magnetic structure is provided without providing another structure. By controlling the dynamic structure,
Reduce the switching magnetic field.

For this purpose, an element shape suitable for controlling a specific magnetic structure, particularly an edge domain, and reducing a switching magnetic field is used. This element shape differs from the prior art in that it does not reduce the area of the edge domain, for example, as in a parallelogram, but rather provides an area of a certain size. In addition, a bias magnetic field is applied to the edge to fix the edge domain and to act as a nucleus for magnetization reversal.

In order to do this, the width of the end portion of the element is made wider than that of the central portion, and the S-type structure of the magnetic domain is stabilized, and as a result, the switching magnetic field is reduced. Further, the switching magnetic field can be reduced more reliably by making the shape asymmetric about the axis of easy magnetization and substantially rotationally symmetric about the axis perpendicular to the film surface. This shape is as shown in FIG. The straight line in the figure indicates the position of the axis of easy magnetization, and the symbol x indicates the position of the axis of rotational symmetry.

In the method of manufacturing a magnetoresistive element according to the present invention, at least a junction region composed of a ferromagnetic / insulator / ferromagnetic laminate is formed, and a mask having a linear pattern crossing the junction region is formed. The bonding region is etched using the mask region, the mask etching is performed a plurality of times at different positions, and the bonding region is processed into a predetermined shape.

In the present invention, the fine structure relating to the junction of the TMR element is manufactured by a method of forming a plurality of intersecting linear patterns. This solves the above-mentioned problem mainly due to the limit performance of lithography. In other words, in the process of fabricating the joint portion using the intersecting linear pattern, the sharpness of the corner is sharp even in a fine rectangular shape because the pattern is formed by the linear pattern having high lithographic fineness and controllability. Patterning with less loss and good shape controllability can be performed. As a result,
A high-performance TMR element having a submicron microstructure capable of high integration can be easily manufactured at a high yield.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) In the first embodiment,
The basic configuration of the present invention will be described using an example of a result of a computer simulation. FIG. 2 is a plan view of the magnetic film according to the first embodiment of the present invention. The magnetic film of the first embodiment has an S-shaped hook shape, and the width of the element is different from the width of the central part of the element. That is, the ferromagnetic film has a width of 0.1 μm at the center and 0.15 μm at the end.
m, the length is 0.4 μm, and the thickness is 1.5 nm.

The shape shown in FIG. 2 is a polygon in which each vertex has an angle of 90 degrees, but is not limited to this, and in particular, each vertex is not limited to 90 degrees. Further, each side does not need to be a straight line, and may be generally formed by a curve.

The element size is not limited to the above, but the maximum width is preferably as small as about 1 μm, and the length is preferably 1 to 10 times the maximum width. The thickness of the ferromagnetic material is preferably 10 nm or less, more preferably 5 nm or less. In particular, for high integration, the element size is preferably small.

In this simulation, Co ₉ Fe is used as the material used for the ferromagnetic layer. However, the magnetic material may be a commonly used magnetic material such as Fe, Co, Ni, a laminated film thereof, or an alloy. In addition, Cu, Au, Ru, Al
For example, a laminated film including a layer made of a metal non-magnetic material may be used.

FIG. 3 shows the hysteresis of this system obtained as a result of simulation. From FIG.
The coercive force Hc is determined to be 242 Oe (Oe). FIG. 3 shows that the difference between the switching magnetic field Hsw and the coercive force Hc is not so large in the magnetoresistance effect element of the present invention. That is, it means that minute magnetic domains are not generated in a complicated manner in the magnetization reversal process.

FIG. 4 shows a change in the pattern of the magnetic domain in the first embodiment. FIG. 4 shows how the magnetic domain structure changes when the external magnetic field H is changed from +1000 Oersted to -1000 Oersted with the left direction being a plus direction.

When the external magnetic field is H = + 300 Oersted (b), the magnetization direction of the end portion starts to change its direction from the easy axis, and when H = 0 Oersted (c), the S-type magnetic domain structure is changed. Stabilize. Furthermore, when the external magnetic field increases in the negative direction (d), it can be seen that the magnetization direction is largely rotated at the wide end portion. Further, when the external magnetic field becomes negatively large (e), a completely inverted magnetic domain structure is obtained.

At the time of the magnetization reversal, the edge domain expands, and the domain wall between the edge domain and the central magnetic domain moves toward the element center, whereby the magnetization is reversed and the external magnetic field is swept. No complex domain structure appears for all values of time. Therefore, it is possible to realize switching with a small magnetic field and a small switching magnetic field required to completely reverse the magnetization.

In this system, the ratio of the residual magnetization to the saturation magnetization is 0.86. This is because an edge domain exists. In general, when a ferromagnetic material has a displaced or disturbed portion in its magnetization direction and the ratio of the residual magnetization to the saturation magnetization is smaller than 1, the ferromagnetic tunnel junction using the ferromagnetic material has a dislocation or disturbed portion. The tunnel magnetoresistance ratio (MR ratio) is reduced as compared with the case where there is no tunnel. However, in this system, since the upper and lower ferromagnetic layers including the insulating layer have the same shape, the upper and lower ferromagnetic layers have almost the same magnetic domain structure. Therefore, although the ratio of the residual magnetization to the saturation magnetization is smaller than 1, there is almost no decrease in the tunnel magnetoresistance in the magnetization direction.

To show that the present invention is effective,
FIG. 5 shows a comparison of the coercive force of several shapes. In this figure, the thickness is 2.0 nm, the length is 0.4 μm,
The simulation results are shown with the center width being 0.1 μm and the end widths in the shapes (f) and (g) being 0.15 μm.

In FIG. 5, for example, a rectangular shape such as shape (b) in which two opposing vertices are cut off has a low coercive force for the same reason as in the case of the above-described parallelogram. However, it can be seen that the smallest coercive force is the shape (g) in the figure, which is the shape of the present invention.

FIG. 6 shows a magnetic domain structure in the case of a parallelogram as another comparative example. As can be seen from the figure, in this case, only in a small area along the hypotenuse, the magnetization is oriented in a direction different from the easy axis of magnetization, and the shape is such that the edge domain is reduced.

On the other hand, in the present invention, the magnetization is distributed as shown in FIG. 2, and the region of the edge domain is expanded.
In the case of the comparative example shown in FIG. 6, the coercive force is 249 Oe, and in the case of the present invention shown in FIG. 2, it is slightly smaller than this.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
It is a top view of a magnetoresistive effect element concerning an embodiment. In the first embodiment, the width of the wide element end is constant, but in the second embodiment, the width of the element end varies within the wide part. It can be seen that, due to this shape, the direction of magnetization changes sequentially in the wide portion.

In this simulation, Co ₉ Fe is used as the material used for the ferromagnetic layer in the same manner as in the first embodiment, but the magnetic material is usually Fe, Co, Ni, their laminated films, alloys, etc. The magnetic material used may be used. Further, a laminated film including a layer made of a metal nonmagnetic material such as Cu, Au, Ru, and Al may be used.

The magnetization curve in the second embodiment is shown in FIG.
Is shown in FIG. 8 shows that the coercive force Hc is as low as 148 Oe (Oe), and the ratio of the residual magnetization to the saturation magnetization is kept as high as 0.96.

(Third Embodiment) In the first and second embodiments, only the ferromagnetic single-layer film has been described. However, at least two ferromagnetic materials and at least one insulating layer interposed therebetween are provided. Similar results can be obtained in the case where a laminated film composed of a layer or a nonmagnetic metal layer is included.

FIG. 9A is a sectional view of a ferromagnetic single tunnel junction structure in which a ferromagnetic layer 1 and a ferromagnetic layer 3 are stacked via an insulating layer 2. By giving the planar structure of the first or second embodiment also to this laminated structure, the magnetoresistive element 10 having a small coercive force can be obtained.

In this case, a so-called spin valve type in which an antiferromagnetic layer is provided outside one of the ferromagnetic layers 1 and 3 may be used. FIG. 9B shows a ferromagnetic layer 1 of FIG. 9A having a three-layer structure in which a ferromagnetic layer 1-1 and a ferromagnetic layer 1-2 are stacked with a nonmagnetic layer 6 interposed therebetween. This three-layer structure may replace the part of the ferromagnetic layer 3. Further, it can be replaced with a multilayer film in which a ferromagnetic layer and a nonmagnetic layer are repeatedly laminated.

FIG. 10 shows a ferromagnetic layer 11 and a ferromagnetic layer 13 laminated via an insulating layer 12, and a ferromagnetic layer 13 joined via a ferromagnetic layer 15 and an insulating layer 14. It is sectional drawing of a tunnel junction structure. By giving the planar structure of the first or second embodiment also to this laminated structure, the magnetoresistive element 20 having a small coercive force can be obtained. In this case, a so-called spin valve type in which an antiferromagnetic layer is provided outside the ferromagnetic layers 1 and 3 may be used.

FIG. 11 shows the ferromagnetic layer 11 of FIG. 10 having a three-layer structure in which a ferromagnetic layer 11-1 and a ferromagnetic layer 11-2 are stacked via a non-magnetic layer 16. In this three-layer structure, an antiferromagnetic coupling recording layer is formed via a nonmagnetic layer 16. This three-layer structure may replace a part of the ferromagnetic layer 15 and can be applied to at least one of the ferromagnetic layers 11 and 15.

For this laminated structure, the first or second
By giving the planar shape of the embodiment, the magnetoresistive element 30 having a small coercive force can be obtained.

FIG. 12 shows the ferromagnetic layer 13 of FIG. 10 having a three-layer structure in which a ferromagnetic layer 13-1 and a ferromagnetic layer 13-2 are stacked via a non-magnetic layer 17. By giving the planar structure of the first or second embodiment also to this laminated structure, the magnetoresistive element 4 having a small coercive force can be provided.
0 can be obtained.

It should be noted that the structure shown in FIG.
At least one of the layers 1 and 15 may have a three-layer structure of a ferromagnetic layer / a nonmagnetic layer / a ferromagnetic layer. In addition, an insulating layer and a ferromagnetic layer may be further laminated a desired number of times in the configuration of FIG.

FIG. 13 shows Co ₉ Fe / Ru / Co ₉ Fe
Holding force H when the planar shape is changed with respect to the three-layer structure of
c are compared, and the shape (d).
It can be seen that the coercive force of (e) can be greatly reduced as compared with a normal rectangular one.

In the third embodiment, the magnetic material, the barrier layer material and the like can be selected as follows. The element and type of the ferromagnetic layer of the present invention are not particularly limited.
Co, Ni or their alloys, magnetite having a large spin polarizability, CrO ₂ , RXMnO ₃ -y (R: rare earth,
X: oxides such as Ca, Ba, Sr) and NiMnS
b, Heusler alloys such as PtMnSb, Zn-Mn-
Magnetic semiconductors such as O, Ti—Mn—O, CdMnP ₂ , and ZnMnP ₂ can be used.

The thickness of the ferromagnetic layer of the present invention must be such that it does not become superparamagnetic, and is preferably at least 0.4 nm. If the thickness is too large, the switching magnetic field becomes large. Therefore, the thickness is preferably 2.5 nm or less. Ag, Cu, Au,
Al, Mg, Si, Bi, Ta, B, C, O, N, P
Even if a small amount of non-magnetic elements such as d, Pt, Zr, Ir, W, Mo, and Nb are contained, it is sufficient as long as the ferromagnetic properties are not lost.

The antiferromagnetic film is made of Fe—Mn, Pt—Mn,
Pt-Cr-Mn, Ni-Mn, Ir-Mn, NiO and the like can be used. Cu, Au, Ru,
Ir, Rh, Ag and the like can be used. When used as antiferromagnetic coupling (pin layer), Ru, I
r, (the case of the recording layer) Rh is preferred, when used as a ferromagnetic coupling, Cu, Au, although Ag is preferable, because adjustment possible by the thickness or the like, not limited thereto.

As the dielectric or insulating layer of the present invention,
Al ₂ O ₃ , SiO ₂ , MgO, AlN, AlON, Ga
Various dielectrics can be used, such as O, Bi ₂ O ₃ , SrTiO ₂ , AlLaO ₃ . These may have oxygen and nitrogen deficiencies.

The thickness of the dielectric layer depends on the junction area of the TMR, and is preferably 3 nm or less. The substrate is not particularly limited, and can be formed on various substrates such as Si, SiO ₂ , Al ₂ O ₃ , and AlN. On top of that, as an underlayer and a protective layer, T
a, a single layer film of Ti, Pt, Pd, Au, etc .;
It is preferable to use a laminated film of t, Ta / Pt, Ti / Pd, Ta / Pd, or the like.

Next, a description will be given of a manufacturing method for manufacturing the magnetoresistive element described in the first to third embodiments. In general, such a device is formed by applying a resist after forming a film, forming a pattern using one of light, electron beam, and X-ray, developing the resist pattern, and ion milling or etching using the resist pattern as a mask. After forming a pattern, the resist is peeled off.

When a magnetoresistive element having a relatively large size, for example, on the order of microns, is manufactured, a TMR film is sputtered, a hard mask such as silicon oxide or silicon nitride is manufactured, and reactive ion etching (RIE) is performed. For example, a pattern of the magnetoresistive element in the present invention as shown in FIGS. 2 and 7 is formed. By ion milling this sample, a magnetoresistance effect element can be manufactured.

A smaller magnetoresistive element, for example, 2
Photolithography can be used to fabricate submicron-sized devices of about 3 μm to about 0.1 μm. In this case, the hard mask having the shape pattern of the magnetoresistive effect element according to the present invention is prepared in advance, and the pattern can be formed.

Electron beam exposure can be used for producing a device having a smaller size, for example, about 0.5 μm or less. However, in this case, since the element itself is small, the shape portion for expanding the edge domain region in the present invention is further reduced, and the fabrication becomes very difficult.

In order to manufacture an element having a small size as described above, the proximity effect correction of an electron beam can be used. Usually, the proximity effect correction is used to correct a proximity effect in a figure caused by backscattering of an electron beam from a substrate and form a correct pattern. For example, when a rectangular pattern is formed, there is a phenomenon in which the amount of accumulated charge is insufficient near the vertex, and the vertex of the rectangle is rounded. In order to clarify the vertex, in the case of an element near the vertex, particularly in the case of an element having a size of about 0.5 μm or less, a normal pattern can be obtained by driving a correction point beam outside the figure to increase the amount of accumulated charges. By applying this method, it is possible to form the shape of the present invention in which the width of the element end is widened.

For example, when the shape shown in FIG. 2 or FIG. 7 of the first or second embodiment is formed, a rectangle is used as a basic pattern, and a correction point beam is driven near each of two opposing vertices to thereby obtain the width of the end. Can be formed.

At this time, as compared with the case of the normal proximity effect correction, the amount of charges to be injected is increased, or the position of injection of the correction point beam is adjusted appropriately, or both are used to recover the vertex. Can be corrected. By doing so, it is possible to form the shape of the present invention. Further, it is also possible to irradiate a plurality of correction point beams, for example, to form the element shape shown in FIG.

As described above, in order to realize the shape of the present invention having a wide rectangular end, the rectangular element can be formed by forming a rectangular element and then applying a correction beam. It is necessary to realize a simple rectangular shape. In the prior art, there is a problem that the corners are rounded to realize such a shape. In the fourth to sixth embodiments, embodiments that solve such a problem will be described.

(Fourth Embodiment) FIG. 14 schematically shows the gist of the manufacturing method of the present invention. As described above, when a rectangular shape is formed by ordinary lithography, when the size is about 0.5 μm or less in photolithography and about 0.2 μm or less in EB lithography, sharpening of the corner of the rectangular shape is significantly lost. As a countermeasure against this problem, the proximity effect correction for light reflection in photolithography and the proximity effect correction for backscattering of electrons in EB lithography have been studied. However, there is a problem that the correction operation requires a long time. If the size is 1 μm, a sufficient effect cannot be obtained.

On the other hand, the width controllability of the linear pattern in lithography is very good, and the width is 0.2 μm or less in photolithography and 0.1 μm in EB lithography.
A width of less than μm can be accurately defined. Applying this fact, as shown in FIG. 14, in order to form a target rectangular pattern 51 (hatched portion), first, a first linear pattern 52 is formed by lithography, and the other region is used as a mask layer. Remove by dry etching. afterwards,
The second linear pattern 53 is formed by lithography so as to be orthogonal to the first linear pattern, and the remaining region outside the rectangle serving as a mask is removed by dry etching. Thereby, a very sharp pattern can be formed as the corner 54 of the rectangular pattern.

Based on the method shown in FIG. 14, various forms can be applied as described in the following embodiments.

First, as a fourth embodiment, the formation of a linear pattern and dry etching are repeated twice to
A method of forming the junction shape of the R element while maintaining the sharpness of the corner will be described.

FIGS. 15 to 26 illustrate the manufacturing process of the TMR element in which the sharpness of the corners is maintained as described above. In each step, the right side (b) shows the top view and the left side (a) shows.
2 shows a cross-sectional view (along the line AA 'in the top view) near the center of the joint.

First, as shown in FIG. 15, a lower wiring layer 62 of Ta and a magnetic tunnel junction of a ferromagnetic / insulator / ferromagnetic structure including a magnetic metal multilayer film are formed on the entire surface of a substrate 61 made of Si. An (MTJ) layer 63 and a Ta contact layer 64 are successively deposited. In the top view, a region to be a TMR element (joining portion) 65 later is indicated by a broken line.

Next, as shown in FIG. 16, after forming a pattern of the lower wiring by photolithography, the lower wiring pattern is formed by reactive dry etching with a mixed gas of Cl ₂ and Ar using a resist (not shown) as a mask. Etch to the substrate surface.

[0079] Then, as shown in FIG. 17, embedding the entire pattern is dry etched in an insulating layer 66 of SiO _x, planarization is performed to the contact layer of Ta is exposed by CMP or an etch-back process.

Next, as shown in FIG. 18, a first linear pattern for forming a joint is formed by a resist 67 so as to extend over a range longer than the intended length of the joint. At this time, the width of the first linear pattern is TM
The minimum dimension of the R element is that it can be easily formed by photolithography with good controllability up to about 0.1 μm.

Next, as shown in FIG. 19, the linear pattern of the resist 67 is transferred to the Ta contact layer 64, and then the resist 67 is removed. At this time, if reactive dry etching is performed using, for example, SF ₆ as an F-based reaction gas, the linear pattern of the resist 67 can be accurately formed by Ta.
Can be transferred to the contact layer 64 and the SiO _x insulating layer 66. Since the magnetic metal of the MTJ layer 63 has resistance to dry etching of the F-based gas, Ta
Only the contact layer 64 can be formed in a linear pattern.

Next, as shown in FIG. 20, the underlying MTJ layer 63 is ion-milled using the Ta contact layer 64 as a mask. Here, Ta has sufficient resistance to ion milling as a hard mask. Therefore, even when Ar ion milling with a beam energy of 400 eV is performed until the lower wiring layer 62 of Ta is exposed, the mask recedes and the film thickness decreases. Is small, and the Ta linear pattern 64 can be satisfactorily transferred to the MTJ layer 63.

For the etching of the MTJ layer 63, reactive dry etching using a mixed gas of Cl ₂ and Ar may be used instead of ion milling. In this case, a diamond layer (DL) is used as the mask layer.
C), C of AlO _x , SiO ₂ , multilayer resist mask, etc.
A material excellent in l-system etching resistance is used. As the insulating film 66 (66 ') to be etched at the same time, it is preferable to use a material such as TEOS with slightly weakened Cl-based etching resistance. In this case, it is necessary to form a mask layer on the contact layer 64 in advance.

Next, as shown in FIG. 21, the contact layer 64 is buried again with an insulating layer 66 ′ of SiO _X and planarized to expose the contact layer 64 of Ta. Subsequently, as shown in FIG.
A resist 68 that defines the other two sides of the joint and has a second linear pattern that is sufficiently long with respect to the joint.
Is formed by photolithography.

Next, as shown in FIG. 23, a second linear pattern of the resist 68 is dry-etched using an F-based reactive gas to form an underlying Ta contact layer 64.
Transfer to

Next, as shown in FIG. 24, using the second linear pattern formed on the Ta contact layer 64 as a hard mask, the MTJ layer 63 is formed by ion milling until it reaches the lower wiring layer 62 of Ta. Etch. Up to this step, the MTJ layer 63 is processed into the shape of the final TMR element 65, and the rectangular shape of the joint is formed while maintaining the sharpness of the corners.

In the fourth embodiment, the case where the shape of the joint is rectangular is shown.
Can be formed not at right angles to the linear pattern but at an angle. In this case, a parallelogram-shaped joint having low coercive force characteristics can also be formed.

Next, as shown in FIG.
Embedded O _x insulating film, planarized to expose the contact layer 64 of Ta. Finally, as shown in FIG.
After depositing an upper wiring layer 69 made of / TiN / AlCu / Ti over the entire surface, patterning is performed by photolithography and dry etching, thereby completing a rectangular TMR element 63 having a right-angled corner.

In addition to the process of forming the upper wiring layer 69 after the formation of the bonding portion 63 as described above, as a step subsequent to FIG. It is also possible to form a second linear pattern, and then perform a linear patterning of the joint portion together with the upper wiring. In this case, there is an advantage that a lithography process for forming the upper wiring is not required.

Further, when the upper wiring is formed simultaneously with the formation of the second linear pattern, the second linear pattern having a wide width can be formed as a rectangular shape suitable for the MRAM. , The width of the upper wiring acting as a main wiring for applying a current magnetic field to the junction of the TMR element can be formed in a wide state in which a higher magnetic field can be applied.

(Fifth Embodiment) Next, as a fifth embodiment, the formation of the linear pattern and the dry etching are repeated twice so that the joint of the TMR element is etched while maintaining the sharpness of the corners. A method of forming a hard mask for performing the process will be described.

FIGS. 27 to 38 illustrate a process for fabricating a fine TMR element having a right-angled corner. FIG. FIG. 4 shows a cross-sectional view (along line AA ′ of the top view). FIG.
29 to FIG. 29 can be exactly the same as the steps of FIG. 15 to FIG. However, 71 is the Si substrate 61, and 72 is T
Reference numeral 73 denotes a lower wiring layer, 73 denotes a magnetic tunnel junction (MTJ) layer having a ferromagnetic / insulator / ferromagnetic structure including a magnetic metal multilayer film, 74 denotes a Ta contact layer, and 75 denotes a TMR element (junction). Area).

Following the step of FIG. 29, as shown in FIG. 30, a Cr mask layer 77 serving as a dry etching mask for defining a junction is deposited on the entire flattened surface.

Next, as shown in FIG. 31, a resist 78 having a first linear pattern is formed by photolithography. Next, as shown in FIG. 32, the first linear pattern of the resist 78 is transferred to the underlying Cr mask layer using dry etching with a mixed gas of Cl ₂ and O ₂ . At this time, since the Cr mask layer is thin, even if dry etching is performed on the Cr mask layer, the base Ta 74,
And the flatness of the SiO _x insulating film 76 is hardly affected.

Next, as shown in FIG. 33, a resist 79 having a second linear pattern is applied to the first linear pattern (7
It is formed by photolithography so as to be orthogonal to 8).

Next, as shown in FIG. 34, the second linear pattern of the resist 79 is also formed by dry etching with a mixed gas of Cl ₂ and O ₂ , using the underlying Cr mask layer 77.
Transfer to In this manner, by the two linear pattern formation and dry etching processes, the Cr mask layer 77 is patterned while maintaining the sharpness of the corners as the shape of the final joint 75.

Here, since the dry etching selectivity between the Cr mask layer 77 and the underlying Ta contact layer 74 is large as described below, the thickness of the Cr mask layer 77 can be formed as thin as about 20 nm. Therefore, FIG.
After the transfer of the first linear pattern, the formation and transfer of the second linear pattern shown in FIG. 33 or FIG. It can be done without.

Next, as shown in FIG. 35, the SF is formed using the Cr mask layer 77 formed as a good rectangular pattern.
The contact layer 74 of Ta is etched by the dry etching of step ₆ .

Next, as shown in FIG. 36, using the Ta contact layer 74 formed as a good rectangular pattern as a mask, the MTJ layer 73 is formed by Ar ion milling until the underlying Ta lower wiring layer 72 is exposed. Etch.

For etching the MTJ layer 73, as in the fourth embodiment, instead of Ar ion milling, Cl _{2 is used.}
Dry etching using a mixed gas of Ar and Ar may be used.

Thereafter, as in the fourth embodiment, FIG.
As shown in FIG. 38, the whole is buried with a SiO _x insulating layer 76 ′ to be flattened, and as shown in FIG.
The process of forming the MR element (junction) 75 is completed.

Here, a non-photosensitive organic material such as DLC or polyimide can be used as a mask layer for defining the junction. When these materials are used as a mask layer, dry etching using O ₂ as a reactive gas can be used for patterning, so that the selectivity with respect to the underlying metal contact layer is very large. Therefore, when patterning the mask layer, there is almost no fear that the flatness of the base is impaired. However, in this case, in the photolithography for defining the linear pattern first, the resist surface such as the silylation process is subjected to O-resistance.
₂ plasma treatment, or it is necessary multilayer resist process. Further, since the DLC and the non-photosensitive organic material are amorphous, they have a feature that a very smooth side wall shape can be obtained even when a fine pattern on the order of 0.1 μm is formed.

Also in the fifth embodiment, it is possible to obtain a rectangular TMR element whose corner is formed at a right angle.

(Sixth Embodiment) Next, as a sixth embodiment, the formation of a linear pattern and dry etching are repeated three times so that the joint shape of the TMR element can be obtained with lower coercive force characteristics. A method of forming will be described.

As can be seen from the graph of the relationship between the shape of the joint and the holding force in FIG. 5, in addition to the rectangular pattern in which the corners in FIG. It is considered that a figure in which two corners are dropped can also obtain relatively low holding force characteristics.

The shape of the joint as shown in FIG.
As shown in FIG. 9, by repeating the formation of the linear patterns 82, 83 and 84 and the dry etching three times, it is possible to accurately obtain the joints 81 indicated by oblique lines.
Furthermore, by repeating such linear pattern formation and etching a plurality of times, it is possible to obtain such a junction shape of a convex polygon with high accuracy.

The process of forming a linear pattern and performing dry etching a plurality of times in this manner includes a method of etching to a joint portion in a linear pattern as in the fourth embodiment and a mask as in the fifth embodiment. Obviously, the method can be applied to both the method of etching only the layer in the linear pattern or the method of using both.

Furthermore, when the above-described method of forming a multiple linear pattern is used for forming a plurality of TMR elements arranged in a lattice in an MRAM, the lithography process can be made more efficient.

(Seventh Embodiment) As a seventh embodiment, a method of manufacturing a TMR element according to a second embodiment (FIG. 7) of the present invention will be described. As shown in FIG. 40, when the first linear pattern 92 is formed by photolithography, a semicircular shape is formed at two rectangular positions at the rectangular end by spot drawing of EB drawing at the same time. A pattern 93 is added. At this time, if a chemically sensitized resist having sensitivity to electron beam and far ultraviolet light such as SAL601 is used as the resist, a mix-and-match method in which photolithography and EB lithography are overlapped can be used. A linear pattern having hemispherical projections, that is, a TMR element 91 can be formed.

Here, although EB lithography is generally a process having a low process throughput, a pattern having a diameter of 50 nm can be drawn at a very high speed only by the above-described spot drawing. For example, if spot drawing is performed with a beam current of 100 pA using a chemically sensitized SAL601 resist, the memory capacity is 1 Gb1t.
It is possible to draw in about 10 ^nine minutes or Wath the spots corresponding to. Therefore, by combining linear pattern exposure of about 0.1 μm width by photolithography and spot exposure of about 50 nm in diameter by EB lithography, an MRAM equivalent to 1 Gbit can be manufactured with high productivity.

The above-described ferromagnetic tunnel junction can be applied to a magnetic recording element, a magneto-resistance effect type magnetic head, a magnetic reproducing device, and the like. Hereinafter, embodiments of application examples of the magnetoresistance effect element of the present invention will be described.

(Eighth Embodiment) In the eighth embodiment,
Magnetic recording device (MRAM) using magnetoresistive element of the present invention
An example in which the present invention is applied will be described.

In general, an MRAM is required to have a small die size and a large capacity. Therefore, not only the wiring width but also the area of each cell is inevitably reduced. However, the switching magnetic field can be reduced by using the magnetoresistance effect element of the present invention. A small write current is required for writing the storage bit, which reduces power consumption and enables high-speed switching. Therefore, the magnetic element of the present invention is suitable for use in an MRAM cell.

FIG. 41 is a sectional view for explaining the configuration of an individual recording element, and FIG. 42 is a schematic circuit diagram of an MRAM.

The MRAM has a plurality of read word lines WL controlled by a row decoder 140, as shown in FIG.
1 (122) and a plurality of bit lines BL (134) controlled by the column data 150 and intersecting with the word lines 122. At each intersection of the word line 122 and the bit line 134, a magnetoresistive element of the present invention (for example, 10, 20, 30, 40 in the third embodiment, or 9 in the seventh embodiment) is provided.
1) and a MOSFET 120 as a switch (conduction control element) whose conduction is controlled by the word line 122.
Is provided. In addition, a write word line WL2 (131) extending in the direction parallel to the read word line 122 and close to the magnetoresistive element 10 is provided.

Each memory element is configured as shown in FIG. The MOSFET 120 is formed on the surface of the semiconductor substrate. 123 and 124 are source / drain regions, the gate electrode 122 is formed to extend, and the word line WL1 is formed.
(122). One of the source / drain regions 124
Through the contact 132 connected to the base wiring 133
Are formed, and the underlying wiring 133 and the bit line 13 are formed.
4, the magnetoresistance effect element 10 of the present invention is formed. Further, a word line WL2 (131) for writing is formed close to the magnetoresistive element 10.

Incidentally, instead of the MOS transistor, a diode is laminated on the magnetoresistive effect element of the present invention to form an MRAM.
May be configured. That is, a diode and a cell comprising the magnetoresistive element of the present invention are stacked and formed on a word line, and a bit line is arranged and formed on the magnetoresistive element,
Further, by arranging a large number of these cells in an array, M
A RAM can be configured. Such an MRAM can be mounted in a memory section of a portable terminal such as a mobile phone.

(Ninth Embodiment) A ninth embodiment describes an example in which the magnetoresistive element of the present invention is applied to a magnetic head.

FIG. 43 is a perspective view of a magnetic head assembly on which the magnetoresistive element 10 (may be 20, 30, 40, or 91) of the third embodiment is mounted. The actuator arm 301 is provided with a hole to be fixed to a fixed shaft in the magnetic disk device, and has a bobbin or the like for holding a drive coil (not shown). A suspension 302 is fixed to one end of the actuator arm 301. A lead wire 304 for writing and reading signals is wired to the tip of the suspension 302, and one end of the lead wire 304 is connected to each electrode of the magnetoresistive element 10 incorporated in the head slider 303. Is connected to the electrode pad 305.

FIG. 44 is a perspective view showing the internal structure of a magnetic disk device (magnetic reproducing device) on which the magnetic head assembly shown in FIG. 43 is mounted. The magnetic disk 311 is mounted on a spindle 312, and is rotated by a motor (not shown) that responds to a control signal from a drive controller (not shown).

The actuator arm 301 has the fixed shaft 31
3 and supports a suspension 302 and a head slider 303 at the tip of the suspension 302. Magnetic disk 3
When 11 rotates, the medium facing surface of the head slider 303 is held in a state of floating above the surface of the magnetic disk 311 by a predetermined amount, and information is recorded and reproduced.

At the base end of the actuator arm 301, a voice coil motor 314, which is a kind of linear motor, is provided. The voice coil motor 314 includes a drive coil (not shown) wound around a bobbin portion of the actuator arm 301, and a magnetic circuit including a permanent magnet and an opposing yoke which are opposed to each other so as to sandwich the coil.

The actuator arm 301 has a fixed shaft 3
It is supported by ball bearings (not shown) provided at two places above and below 13, and can be freely rotated and slid by a voice coil motor 314.

As described above, the magnetic head or the magnetic reproducing apparatus using the magnetoresistive effect element of the present invention can operate at higher speed and more stably than the conventional magnetoresistive effect element, and can increase the capacity.

[0125]

According to the magnetoresistance effect element of the present invention,
Low coercive force and small switching magnetic field. When this element is used as a memory cell of a magnetic memory, a write wiring current for generating a magnetic field required for magnetization reversal can be reduced. Therefore, the magnetic memory using the magnetic element of the present invention as a memory cell can achieve high integration, reduce power consumption, and increase switching speed.

Further, according to the method of manufacturing a magnetoresistive effect element of the present invention, the above element can be manufactured by a simple process with a high yield.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a magnetoresistance effect element according to the present invention.

FIG. 2 is a plan view showing a direction of magnetization in the magnetoresistive element according to the first embodiment of the present invention.

FIG. 3 is a magnetization hysteresis diagram of the magnetoresistive element according to the first embodiment.

FIG. 4 is a view showing a magnetization reversal process of the magnetoresistive element according to the first embodiment.

FIG. 5 is a magnetoresistance effect element (g) according to the first embodiment;
The coercive force of the element having various other shapes ((a) ~
The figure which compared with the coercive force of (f)).

FIG. 6 is a diagram showing one shape and a direction of magnetization of a comparative example with respect to the present invention.

FIG. 7 is a plan view showing the shape and the direction of magnetization of a magnetoresistive element according to a second embodiment of the present invention.

FIG. 8 is a magnetization hysteresis diagram of the magnetoresistive element according to the second embodiment.

FIG. 9 is a sectional view of a magnetoresistive element according to a third embodiment of the present invention.

FIG. 10 is a sectional view of another magnetoresistive element according to the third embodiment.

FIG. 11 is a sectional view of still another magnetoresistive element according to the third embodiment.

FIG. 12 is a sectional view of still another magnetoresistive element according to the third embodiment.

FIG. 13 is a diagram comparing the coercive force of the magnetoresistive element (e) according to the third embodiment with the coercive forces of other elements ((a) to (d)) having various shapes.

FIG. 14 is a schematic plan view illustrating the concept of a method of forming a magnetoresistive element according to the present invention.

FIGS. 15A and 15B are a cross-sectional view and a plan view of an element for explaining a manufacturing process of a magnetoresistive element according to a fourth embodiment of the present invention.

FIGS. 16A and 16B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 17A and 17B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 18A and 18B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 19A and 19B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIG. 20 is a cross-sectional view (a) and a plan view (b) of an element for explaining a step following the previous figure.

FIGS. 21A and 21B are a cross-sectional view and a plan view, respectively, of an element illustrating a step following the previous figure.

FIGS. 22A and 22B are a cross-sectional view and a plan view of a device illustrating a step following the previous figure.

FIGS. 23A and 23B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 24A and 24B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 25A and 25B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 26A and 26B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 27A and 27B are a cross-sectional view and a plan view of an element for explaining a manufacturing process of a magnetoresistive element according to a fifth embodiment of the present invention.

FIGS. 28A and 28B are a cross-sectional view and a plan view, respectively, of an element for explaining a step following the previous figure.

FIGS. 29A and 29B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 30A and 30B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 31A and 31B are a cross-sectional view and a plan view, respectively, of an element for explaining a step following the previous figure.

FIG. 32 is a cross-sectional view (a) and a plan view (b) of an element for explaining a step following the previous figure.

FIG. 33 is a cross-sectional view (a) and a plan view (b) of an element for explaining a step following the previous figure.

34A and 34B are a cross-sectional view and a plan view of a device illustrating a step following the previous figure.

FIGS. 35A and 35B are a cross-sectional view and a plan view of an element for explaining a step following the previous step; FIGS.

FIGS. 36A and 36B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

FIGS. 37A and 37B are a cross-sectional view and a plan view of an element for explaining a step following the previous figure.

38A and 38B are a cross-sectional view and a plan view of a device illustrating a step following the previous figure.

FIG. 39 is a schematic plan view illustrating the method for manufacturing the magnetoresistive element according to the sixth embodiment of the present invention.

FIG. 40 is a schematic plan view illustrating the method for manufacturing the magnetoresistive element according to the seventh embodiment of the present invention.

FIG. 41 shows an MRAM according to an eighth embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a configuration of a cell.

FIG. 42 is a circuit diagram of an MRAM according to an eighth embodiment.

FIG. 43 is a schematic perspective view of a magnetic head according to a ninth embodiment of the present invention.

FIG. 44 is a schematic perspective view of a magnetic reproducing apparatus using a magnetic head according to a ninth embodiment.

FIG. 45 is a view showing a general magnetic structure appearing in a minute magnetic body.

FIG. 46 is a view showing step by step a pair of a cross-sectional view and a plan view of a manufacturing process of a conventional magnetoresistance effect element.

[Explanation of symbols]

1, 3, 5, 11, 13, 15, 11-1, 11-2 ...
Ferromagnetic layer 2, 12, 14 ... Barrier layer 16, 17 ... Non-magnetic layer 10, 20, 30, 40 ... Magnetoresistance effect element 61, 71 ... Si substrate 62, 72 ... Lower wiring line layer 63, 73 ... MTJ layer 64, 74 ... contact layer 65, 75 ... junction (TMR element) 66, 66 ', 76, 76' ... insulating layer 67, 68, 77, 78 ... photoresist (mask layer) 69, 80 ... upper wiring layer 81 , 91 ... junction (TMR element) 82, 92 ... first linear pattern 83, 94 ... second linear pattern 84 ... third linear pattern 93 ... EB drawing pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 10/16 H01F 10/32 10/32 H01L 43/12 H01L 27/105 G01R 33/06 R 43/12 H01L 27/10 447 (72) Inventor Kentaro Nakajima 1st Toshiba R & D Center, Komukai-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Minoru Amano 1 Toshiba-cho, Komukai Toshiba-cho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Address: Toshiba R & D Center (72) Inventor: Masayuki Sunai 1: Komukai Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa 1F, Komukai Toshiba-cho, Toshiba R & D Center F-term (reference) 2G017 AA01 AB07 AD55 AD65 5D034 BA03 BA08 BA15 DA07 5E049 AA01 AA04 AA07 AA09 AC00 AC05 BA12 CB02 DB12 5F083 FZ10 GA09 GA27 GA30 JA39 JA56 PR01 PR03 PR04 PR39 PR40

Claims (11)

[Claims] A first ferromagnetic layer, an insulator layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the insulator layer. A tunnel current flows between the first ferromagnetic layer and the second ferromagnetic layer by tunneling through an insulator layer, and the tunnel current or the first and second ferromagnetic layers
A magneto-resistance effect element for detecting a voltage generated between the ferromagnetic layers of the magneto-resistance effect element, wherein a planar shape of the magneto-resistance effect element is larger at an end portion than at a central portion. 2. A method according to claim 1, wherein at least one of said first and second ferromagnetic layers has a third ferromagnetic layer, a non-magnetic layer formed on said third ferromagnetic layer, and a non-magnetic layer formed on said non-magnetic layer. 2. The magnetoresistive element according to claim 1, further comprising a fourth ferromagnetic layer formed on the substrate. 3. A first ferromagnetic layer, a first insulator layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the first insulator layer. A magnetoresistive element having a layer, a second insulator layer formed on the second ferromagnetic layer, and a third ferromagnetic layer formed on the second insulator layer. A magnetoresistive element whose planar shape has a width at an end portion larger than a width at a central portion. 4. At least one of the first, second, and third ferromagnetic layers includes a fourth ferromagnetic layer, a non-magnetic layer formed on the fourth ferromagnetic layer, 4. The magnetoresistive element according to claim 3, further comprising a fifth ferromagnetic layer formed on the nonmagnetic layer. 5. The magnetoresistive element according to claim 1, wherein the planar shape is asymmetric with respect to the axis of easy magnetization and substantially rotationally symmetric about a direction perpendicular to the film surface. 6. A plurality of word lines, a plurality of bit lines crossing the plurality of word lines, and a connection between the bit lines and the word lines at respective intersections of the plurality of word lines and the plurality of bit lines. A magnetic random access memory comprising the magnetoresistive element according to claim 1. 7. A portable terminal device comprising the magnetic random access memory according to claim 6. 8. A magnetic head comprising the magneto-resistive element according to claim 1 in a magnetic detecting section. 9. A magnetic reproducing apparatus comprising: a magnetic head provided with a magnetoresistive element according to claim 1 mounted on a magnetic detector. 10. A bonding region comprising at least a ferromagnetic / insulator / ferromagnetic laminate is formed, and said bonding region is etched using a mask having a linear pattern crossing said bonding region. Is carried out a plurality of times while changing the position, and the joining region is processed into a predetermined shape. 11. The method of manufacturing a magnetoresistive element according to claim 10, wherein the corners having the predetermined shape are further processed by an electron beam.